High tibial
osteotomies were performed on 136 osteoarthritic knees for correction of varus
deformity. Before
osteotomy all patients experienced moderate or severe
pain, and the knees showed lateral thrust on weight-bearing. The patients were followed up for one to five years. Marked relief of
pain was obtained in 112 knees, and the patients were satisfied with the result of operation in 122. These painless knees showed no lateral thrust, and in the majority the
deformity had been adequately corrected, with post-operative femoro-tibial angles (standing) ranging from 165 degrees to 174 degrees. Four of 28 knees with femoro-tibial angles of 175 degrees to 179 degrees, when measured one year after operation, showed recurrence of varus
deformity three years after
osteotomy. Preoperative ranges of knee motion were well maintained after
osteotomy even when arthrotomy had also been undertaken. Intra-articular assessment in two patients, several years after operation, showed that the most degenerated portions of the articular surface were completely covered by a fibrocartilagenous layer, with no bare bone. High tibial
osteotomy is most effective in osteoarthritic knees with varus
deformity, when correction is made to a femoro-tibial angle (standing) of 170 degrees (10 degrees valgus).